1. Technical Field
The subject matter described here generally relates to wind turbines, and, more particularly, to differential vibration sensing and control of wind turbines.
2. Related Art
A wind turbine is a machine for converting the kinetic energy in wind into mechanical energy. If the mechanical energy is used directly by the machinery, such as to pump water or to grind wheat, then the wind turbine may be referred to as a windmill. Similarly, if the mechanical energy is converted to electricity, then the machine may also be referred to as a wind generator or wind power plant.
Vibrations in various components of a wind turbine may considerably reduce the life of those components and/or lead to early fatigue failures. These vibrations are typically measured with respect to a stationary reference point using accelerometers arranged at critical locations on the components of interest. However, such conventional approaches to vibration sensing do not adequately protect the wind turbine and can lead to unnecessary system shutdown “trips.”